Notes on the Bible, by Albert Barnes, , at sacred-texts.com
The punishment of the dwellers in Jerusalem.
Them that have charge - The angels who have charge to execute God's sentence.
Every man - "angels," not "men."
Six men - angels of wrath - figurative of destruction. They come from the north, the quarter from which invading armies entered the holy land. These "six" angels, with the "one among them," a superior over the six, make up the number "seven," a number symbolic of God's covenant with His people.
The higher gate - The north gate of the court of the priests. The temple rose by platforms; as there was a north gate to the outer and also to the inner court, the latter was probably distinguished as the "higher gate." It was built by Jotham Kg2 15:35.
Clothed with linen - The priestly garment Exo 28:6, Exo 28:8; Lev 16:4. This "One Man" (Compare Dan 10:5; Rev 1:13) was the "angel of the covenant," the great high priest, superior to those by whom He was surrounded, receiving direct communication from the Lord, taking the coals of vengeance from between the cherubim Eze 10:2, but coming with mercy to the contrite as well as with vengeance to the impenitent; these are attributes of Jesus Christ Joh 5:30; Luk 2:34; Mat 9:13; Joh 6:39.
A writer's inkhorn - Usually a flat case about nine inches long, by an inch and a quarter broad, and half an inch thick, the hollow of which serves to contain the reed pens and penknife. At one end is the ink-vessel which is twice as heavy as the shaft. The latter is passed through the girdle and prevented from slipping through by the projecting ink-vessel. The whole is usually of polished metal, brass, copper or silver. The man with the inkhorn has to write in the Book of Life the names of those who shall be marked. The metaphor is from the custom of registering the names of the Israelites in public rolls. Compare Exo 32:33; Psa 69:28; Isa 4:3; Phi 4:3; Rev 3:5.
Cherub - The singular is put collectively for the "cherubim," which were upon the mercy-seat of the ark in the holy of holies, the proper seat of the glory of the Lord in the midst of Israel. God is represented as "arising" from between the cherubim to scatter His enemies Num 10:35.
mercy precedes judgment. So in the case of Sodom Gen. 19, and in the last day Luk 21:18, Luk 21:28; Rev 7:1. This accords with the eschatological character of the predictions in this chapter (see the introduction of Ezekiel).
A mark - literally, "Tau," the name of the last letter of the Hebrew alphabet. The old form of the letter was that of a cross. The Jews have interpreted this sign variously, some considering that "Tau," being the last of the Hebrew letters, and so closing the alphabet, denoted completeness, and thus the mark indicated the completeness of the sorrow for sin in those upon whom it was placed. Others again observed that "Tau" was the first letter of Torah ("the Law") and that the foreheads were marked as of men obedient to the Law. Christians, noting the resemblance of this letter in its most ancient form to a cross, have seen herein a reference to the cross with which Christians were signed. The custom for pagan gods and their votaries to bear certain marks furnishes instances, in which God was pleased to employ symbolism, generally in use, to express higher and more divine truth. The sign of the cross in baptism is an outward sign of the designation of God's elect, who at the last day shall be exempted from the destruction of the ungodly Mat 24:22, Mat 24:31.
Begin at my sanctuary - The first to be punished were those who had brought idolatry nearest to the holy place. The "ancient men," i. e., the 25 men who had stood with their backs to the altar Eze 8:16 were the first to be slain.
Defile the house - By filling the temple and its courts with the bodies of the slain. See Num 19:11.
Left - The prophet was left alone, all who had been around him were slain.